1. Field of the Invention
The present invention relates to preventing human errors while disengaging components from hot pluggable systems while the systems are operational.
2. Description of the Related Art
Hot pluggable computer systems are computer systems in which components can be removed, e.g., for repair, and then reinstalled, all while the remainder of the system remains operational. As an example, a computer system might include several disk drives, any one of which can fail. With hot pluggable technology, the failed disk drive can be removed from the system without having to deenergize the system or otherwise make it unavailable. Likewise, a disk drive can be added to a hot pluggable system while the system is operational. Together with redundancies afforded by, e.g., RAID technology, hot pluggable technology promotes high system availability.
Accordingly, hot pluggable systems are designed to support non-stop operation. Typically, hot pluggable systems include row after row of virtually identical components, and lights next to each component are illuminated as appropriate to indicate whether the component is functional or whether it has failed or otherwise requires maintenance. Or, a computer display might be used to indicate the status of each component. Or yet again, all system components might be locked in place, requiring a system administrator to unlock a component to permit its removal. In all cases, as recognized by the present invention, current systems rely on a person to correctly disengage and/or remove failed components, and, despite the indications that are available, it happens that human error in removing properly functioning components instead of failed components are the main cause for hot pluggable systems becoming unintentionally unavailable. The present invention makes the critical observation that what is missing in the prior art is an automatic interlock between the logic that detects a failure in a hot pluggable component and the logic that locks the hot pluggable component in place.
A hot pluggable computer system includes a hot pluggable component that in turn includes a housing. A component bay is configured for receiving the component therein, with the component being positionable in an operate position in the bay in which the component is accessible to other parts of the system. Also, a failure detect module is associated with the component to generate a fail signal if the component malfunctions. Moreover, a lock is associated with the bay, and the lock is movable between a xe2x80x9clockxe2x80x9d position, wherein the lock engages the housing to hold the component in the bay when the component is in the operate position, and a release position, wherein the lock is distanced from the housing and the component can be moved from the operate position. In accordance with the disclosure below, the lock is automatically moved to the release position in response to the fail signal and/or inputs from a user or system administrator.
In a first embodiment, the lock is spring-biased toward the lock position. The lock has an incline surface, such that as the component is being installed, the component rides against the incline surface to urge the lock toward the release position when the component is moved toward the operate position. In this embodiment, an electromagnet is associated with the lock and is selectively energizable to move the lock. Also, an interlock module is electrically coupled to the electromagnet to actuate the electromagnet upon receipt of the fail signal. If desired, the fail detect module can be unitary with the interlock module. A mechanical release can be coupled to the lock to move the lock to the release position regardless of whether a fail signal is present.
In a second embodiment, the lock includes at least one bolt pivotably mounted in the bay. The bolt is coupled to a motor, and the motor moves the bolt between the lock position and the release position. The preferred bolt is a variable length bolt that is biased toward an extended configuration, wherein at least a distal segment of the bolt can protrude into a cavity of the housing of the hot pluggable component, and a retracted configuration, wherein the distal segment abuts the housing when the cavity is not properly aligned with the bolt. In a specific embodiment, the bolt includes a proximal segment and a sleeve reciprocatingly engaged with the proximal segment, with the sleeve defining at least a portion of the distal segment of the bolt.
In another aspect, a computer-implemented method is disclosed for unlocking a hot pluggable component from an associated system device. The method includes locking the hot pluggable component, and then receiving a signal representative of a malfunction of the component. In response to the signal, the component is automatically unlocked.
In still another aspect, a computer program device includes a computer program storage device that is readable by a digital processing apparatus. A program is on the program storage device, and the program includes instructions that are executable by the digital processing apparatus for interlocking, with a fail signal representing a malfunction of a component, the release of the component from a system device. The program includes computer readable code means for receiving the fail signal. Also, the program includes computer readable code means for actuating a lock mechanism associated with the component to permit the component to be manually removed from the system device in response to the fail signal.
In yet another aspect, a hot pluggable system includes a system device including a lock mechanism, and a hot pluggable component can be engaged with the lock mechanism when the component is appropriately positioned to permit communication between the component and devices in the system other than the system device. The system further includes a fail detect module that is coupled to the component to detect malfunctions thereof and to generate fail signals in response thereto. An interlock module is coupled to the fail detect module and to the lock mechanism to automatically actuate the lock mechanism if a fail signal is received. The interlock module can receive control input from a system administrator. It will be appreciated that the modules cooperate to establish an interlock between fail detection and component locking.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: